Thursday, September 16, 2010

A quiet weekend coming up...

The pic is the forecast 23 hours ahead from now. You will have by now noticed the effects of the short sharp fronts crossing your area at upward of 40 knots early Friday. The wind chill factor will be severe. In fact the high altitude northwest arch has already formed above me at 40S.

Let me put those all those numbers on the pic (hectopascals) into some context. Take 1000 hPa as the base. Nice fluffy clouds coasting along on a typical sunny day with a 15knot SW breeze. 1030 is the ultimate summer day, cloudless, still air and the birds singing. 30hPa the other way from your base at around 970 is usually a gale-force, spume-riven full on storm. Anything greater then than that is cyclone/hurricane material. (I have been at sea doing SAR at 965, not nice) This upcoming storm is in that territory, being bigger than Oz and having been down around 950hPa. And you will feel it as it crosses below New Zealand. It is over 3000 km in diameter.

I'd say batten the hatches and have nice weekend. Indoors.

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